Bypass Valve? How to Adjust?

   / Bypass Valve? How to Adjust? #1  

TerryR

Veteran Member
Joined
Jan 5, 2009
Messages
1,123
Location
Boone, NC
Tractor
JD 870
Anyone know what the proper name for this is, and how to adjust it?

valve.jpg

It's on my Peruzzo ditch and bank mower. It's on the cylinder that swings the mower head out to the side. It's purpose is to limit damage if the mower head hits an obstacle when being swung out. But it seems to be set to release at too low a pressure for my hilly property. When I try to swing the head out while the tractor is pointed down a steep hill (21 degrees - 40%) and the head has to be pushed back up the hill, or on a side hill where the head has to swing up hill, the valve releases and the head doesn't move. This is true even if the mower is off the ground.

So I think the solution is to set the valve for a higher relief pressure. But how?

Taking off the cap exposes a threaded rod, with a hex socket in the end. So I suppose one takes off the cap, loosens the jam nut, and turns the threaded rod. But which direction sets it for a higher relied pressure? How many turns to have an effect?
Any info welcome.
 
   / Bypass Valve? How to Adjust? #2  
It's adjusted exactly how you said. I would increase just enough so it works on those hills. Don't increase it too much as you still want that safety featury work.

Rotate right, increase pressure. Rotate left, decrease pressure. It just pushes a spring inside. So you adjust it's tension.
 
   / Bypass Valve? How to Adjust? #3  
Their are instructions online for “cross over relief valve”. While this isn’t one of those the concept is the same. As stated above you don’t want the pressure set too high.
 
   / Bypass Valve? How to Adjust?
  • Thread Starter
#4  
Thanks, guys.

Based on your comments I went out and tried to adjust it. I had difficulty setting up a reliable test situation, so I'm not too confident of the results, but they seemed contrary to what I expected.

I made several adjustments turning the rod clockwise, a total of four revolutions, which seemed to have no effect. So I reset it and then turned it a turn and a half counter-clockwise and that seemed to help.

I'd gotten to a point in my mowing that I didn't have a lot of occasion to extend the mower uphill, so I'm not sure whether I fixed it yet.
 

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